User blog comment:TheMightyCookie!/Egg Move (I Have a Problem.)/@comment-32452525-20171120002944

That means it’ll just take longer for the breed/they have a lower chance to breed.

The reason of this is because of their combination of OT and if they’re same species or not. The best chance is same OT and different Species, OR vice versa, both have an 80% chance if I am correct.